Range of motion evaluation in orthopedic surgery

ABSTRACT

A system and method may be used to evaluate soft tissue. A hip joint evaluation may use an adjustable spacer, such as varying sized physical spacers or an inflatable bladder, along with a sensor to measure force, pressure, gap distance, or the like, for example during a range of motion test. A method may include using a maximum pressure during the range of motion test to determine a maximum pressure during the range of motion test. The maximum pressure may be output for display on a user interface.

CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.16/262,482, filed Jan. 30, 2019, now abandoned, which claims the benefitof priority to U.S. Provisional Application Nos. 62/625,706, filed Feb.2, 2018, titled “SOFT TISSUE BALANCING IN ROBOTIC KNEE SURGERY”;62/697,227, filed Jul. 12, 2018, titled “SOFT TISSUE BALANCING INROBOTIC KNEE SURGERY”; and 62/697,220, filed Jul. 12, 2018, titled“RANGE OF MOTION EVALUATION IN ORTHOPEDIC SURGERY” each of which ishereby incorporated herein by reference in its entirety.

BACKGROUND

Computer-assisted surgery has been developed in order to help a surgeonin altering bones, and in positioning and orienting implants to adesired location. Computer-assisted surgery may encompass a wide rangeof devices, including surgical navigation, pre-operative planning, andvarious robotic devices. One area where computer-assisted surgery haspotential is in orthopedic joint repair or replacement surgeries. Forexample, post-operative range of motion is an important considerationfor a surgeon during orthopedic procedures. However, when performingorthopedic surgery on joints, range of motion evaluations areconventionally done by eye, with the surgeon qualitatively assessing thelimits of patient's range of motion. The conventional technique mayresult in errors or lack precision.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 illustrates an adjustable spacer used in a surgical procedure inaccordance with some embodiments.

FIG. 2 illustrates a surgical technique in accordance with someembodiments.

FIG. 3 illustrates an adjustable spacer and graphs showing effects ofthe adjustable spacer in accordance with some embodiments.

FIG. 4 illustrates a system for using an adjustable spacer with arobotic surgical device in accordance with some embodiments.

FIG. 5 illustrates a flowchart showing a technique for using anadjustable spacer in a surgical knee procedure in accordance with someembodiments.

FIG. 6 illustrates a system for performing techniques described herein,in accordance with some embodiments.

FIG. 7 illustrates a block diagram of an example of a machine upon whichany one or more of the techniques discussed herein may perform inaccordance with some embodiments.

DETAILED DESCRIPTION

Systems and methods for using an adjustable spacer in a surgicalprocedure are provided herein. The systems described herein may includeusing an adjustable spacer for use during a range of motion test. In anexample, the adjustable spacer may be controlled by fixing pressure orfixing distance (e.g., of a neck of a trial for use in an orthopedicprocedure, such as on a shoulder or hip) during an evaluation. Theadjustable spacer systems and methods described herein may be used witha robotic surgical device.

Robotics offer a useful tool for assisting the surgeon in the surgicalfield. A robotic device may assist in the surgical field performingtasks such as biopsies, electrode implantation for functional procedures(e.g., stimulation of the cerebral cortex, deep brain stimulation), openskull surgical procedures, endoscopic interventions, other “key-hole”procedures, arthroplasty procedures, such as total or partial kneereplacement, hip replacement, shoulder implant procedures, or the like.In an example, a surgical procedure may use a surgical robot. Thesurgical robot may include a robotic arm for performing operations. Atracking system may be used to determine a relative location of thesurgical robot or robotic arm within a coordinate system or a surgicalfield. The surgical robot may have a different coordinate system ortracking system (e.g., using known movements of the surgical robot). Therobotic arm may include an end effector of the robotic arm of thesurgical robot, which may use sensors, such as a gyroscope,magnetoscope, accelerometer, etc. In an example, a processor may be usedto process information, such as tracking information, operationparameters, applied force, location, or the like.

The systems and methods described herein provide an expandable oradjustable component for use within an orthopedic surgical procedure.For example, a shoulder or hip procedure may include using an adjustablespacer during a range of motion test. The adjustable spacer may includea component inflatable by a pump. The pump may maintain a fixed distanceor fixed pressure in the component, for example throughout the range ofmotion test. Using a fixed distance, a maximum pressure or force may bedetermined (or various pressures or forces throughout the range ofmotion). Using a fixed pressure, various distances or a maximum distancemay be determined during the range of motion test. The adjustable spacermay be a part of a trial or insert for use in a surgical procedure, forexample, a femoral stem or humeral stem may include the adjustablespacer. In another example, a femoral head, humeral head, or glenospheremay include the adjustable spacer. A determined pressure or distance(e.g., maximum throughout a range of motion) may be used to adjust apreoperative plan. For example, a planned implant may be modified to belarger or smaller.

FIG. 1 illustrates an adjustable spacer 102 within a neck component usedin a surgical procedure in accordance with some embodiments. The diagram100 illustrated in FIG. 1 shows the adjustable spacer 102 as part of ahip trial or hip implant, but may also be used with a shoulder trial ora shoulder implant, or for use with other orthopedic surgical trials orimplants (e.g., knee). The adjustable spacer 102 may be within a neckcomponent, which may be connected to a shaft 104 and a head 106. Theneck therefore may be inflated to change the distance between a proximalend of the shaft 104 and a distal end of the head 106 (defining thedistal end of the head 106 to be opposite a proximal end configured tofit into an acetabular component 108, such as a trial). A distal end ofthe shaft 104 may be embedded into a femur, an acetabulum, or a humerusof a patient (or in the glenoid of the patient in a reverse shoulderarthroplasty procedure).

The neck may experience pressure (e.g., a compression force) frombetween the head 106 (imparted, for example by the acetabular component108 onto the head 106) and the shaft 104. In an example, the distance ofthe neck is controlled to remain equal throughout a range of motiontest, while allowing pressure to change. In another example, thepressure in the neck is controlled and held equal throughout a range ofmotion test while the distance is allowed to change.

The adjustable spacer 102 may be inflated or adjusted using a pump(e.g., which may be controlled by a robotic surgical system in anexample). An inflated component of the adjustable spacer 102 may be usedduring a range of motion test, such as for a hip or shoulder procedure.In an example, a fixed distance or a fixed pressure for the adjustablespacer 102 (e.g., as identified in a surgical plan, which may be apreoperative plan or a plan generated or modified intraoperatively) maybe used during the range of motion test. An extrema may be determined,such as a maximum or minimum pressure (for a fixed distance) or maximumor minimum distance (for a fixed pressure) during the range of motiontest. The extrema may be output, such as for display on a user interfaceor for use in automatically adjusting a parameter of a surgical plan.The surgical plan may be modified based on soft tissue tension, a changein implant sizing, or the like, such as based on the extrema.

In an example, an adjustable spacer similar to that described above(102) may be used with a patella. For example, an inflatable trial maybe used to replace a patella before a range of motion test is conducted.The inflatable trial may be used at a fixed distance or fixed pressure,and a maximum pressure or maximum distance (respectively) may bedetermined for the inflatable trial throughout the range of motion. Inan example, the inflatable trial may replace the patella and be usedafter the patella is cut. The range of motion test may be conducted tocheck stability in the patella with the inflatable trial. In anotherexample, the inflatable trial may be used to place the patella at a newheight or distance away from the knee joint, and the range of motiontest may use the inflatable trial and the patella together to checkstability.

The inflatable trial may be used to check different fixed distances(e.g., away from the knee joint) to determine an optimal fixed distancefor range of motion, for example to minimize pressure on the trial. Inanother example, a fixed pressure may be used in the inflatable trial todetermine a range of distances throughout the range of motion (e.g., todetermine a maximum distance needed for a fixed pressure). Apreoperative plan may be used for any initial testing, and the plan maybe automatically adjusted based on results (e.g., changing an initialdistance, pressure, or volume).

The surgeon may adjust any planned resections, test, and record theforces (e.g., pressure) captured by a force or pressure sensorthroughout a range of motion. This procedure may be repeated asnecessary until the plan results in the desired expected tension values.The surgeon may remove bone according to the final plan. Once sufficientbone is removed according to the plan, range of motion may be confirmedwith the adjustable spacer 102, or a trial implant.

FIG. 2 illustrates a surgical technique 200 in accordance with someembodiments. The technique 200 uses an adjustable spacer to perform arange of motion test. The technique 200 includes initiating orgenerating a plan (e.g., preoperatively) at 201, such as using a userinterface 202. The plan may be for an orthopedic procedure, such as fora hip or shoulder.

The user interface 202 may include a visual depiction of a range ofmotion test. For example, the user interface 202 includes a range ofmotion visualization component 208. In an example, the range of motionvisualization component 208 may be an actual range of motion of apatient, a potential range of motion, an ideal range of motion, apossible range of motion, or a planned range of motion (e.g., afterorthopedic surgery). The range of motion may be for a shoulder or hip,in an example. The range of motion visualization component 208 mayinclude one or more zones, such as a green zone 210 representing apressure or distance for an adjustable spacer within a first tolerance.A yellow zone 212 may represent a pressure or distance between the firsttolerance and a second tolerance (e.g., with a potentially problematicpressure or distance). A red zone 214 may represent a pressure ordistance beyond the second tolerance (e.g., traversing a plannedpressure or distance maximum or minimum). The tolerances or zones may beselected such as preoperatively, in a plan, by a surgeon, etc.

The zones 210-214 may be generated based on the range of motion test (orpotential, possible, or ideal range of motion) with a given neck lengthof an adjustable spacer between a shaft (e.g., femoral shaft) and a cupor head (for a hip procedure). In an example, the range of motionvisualization component 208 illustrates a pressure map for threedifferent fixed neck lengths, 210, 212, and 214. The pressure maps mayshow different pressures at different points around the range of motionfor the respective neck lengths.

In another example, a pressure in the adjustable spacer may be fixed andthe neck length allowed to change. In this example, the range of motionvisualization component 208 illustrates a neck length map for threedifferent fixed pressures, 210, 212, and 214. In this example, the necklengths change throughout the range of motion for each fixed pressure.

In either of the two above examples (fixed neck length or fixedpressure), a single range of motion test may be run or multiple range ofmotion tests may be run, such as at different fixed pressures or necklengths (the three examples are shown for illustration purposes). Theresulting map (a pressure map when the neck length is fixed or a necklength map when the pressure is fixed) may be used to change apreoperative plan. For example, a maximum pressure or maximum necklength may be used from the range of motion visualization component 208to change a planned neck length, implant size, trial size, or the like.

The technique 200 includes an operation 204 to capture balance during arange of motion test, for example using an adjustable spacer. Theadjustable spacer is described in more detail below. The technique 200may include using feedback from the range of motion test to adjust theplan (e.g., automatically change a parameter of the preoperative planbased on the range of motion test, such as balance information, amaximum or minimum distance, range of motion, or implant or trialangle), for example by fine tuning the plan at operation 206. Thetechnique 200 may include performing a resection, burr action, orotherwise reduce bone. The technique 200 may include evaluating balancein soft tissue or for range of motion using the adjustable spacer.

In an example, the technique 200 may include using an optical tracker totrack components of a surgery. For example, tracked components mayinclude a leg, an arm, a bone, a tool, or the like. The technique 200may include performing a range of motion test to evaluate pressure ordistance in a shoulder or hip joint over a range. Optical trackers maybe used to determine various attributes of bones or soft tissue duringthe range of motion test. For example, distance traveled by the leg orarm throughout the range of motion test, angle of bone during the rangeof motion test (e.g., a maximum angle), distance at various points orthroughout the range of motion test, or the like.

In an example, the distance or pressure may be shown on a user interfaceduring the range of motion test. The distance may be shown based on aplanned bone removal (or a resection). The planned bone removal may beshown on the user interface, along with distance or pressure throughoutthe range of motion test to display differences or issues that may arisebased on the planned bone removal and the evaluated pressure ordistance.

The technique 200 may include establishing the preoperative plan andshowing the hip or shoulder with the planned resections on the userinterface. Then as distance or pressure are determined throughout therange of motion test, the distance or pressure are displayed on the userinterface with the planned bone removal. This combination of preplannedbone removal visualization with actual measured distance or pressureinformation allows for evaluation of the planned bone removal with realfeedback. This combination also allows for evaluating the ultimatedistance or pressure with the planned bone removal rather than distanceor pressure pre-bone removal, which may not ultimately be accurate. Thecombination further allows for accurate planning of what the soft tissuebalancing (e.g., rotation of the leg or arm relative to the hip orshoulder joint, respectively) will be after the planned bone removalwithout needing to actually perform the bone removal. This allows foraccurate planning, and modification to the bone removal may be made.

In an example the technique 200 may include displaying the measured andactual neck distance or pressure with the planned bone removal byreference to a hip or shoulder, and an axis or a plane of a bone (e.g.,a femoral axis). The distance or pressure may be measured using a sensoron an adjustable spacer as described throughout this disclosure.

In an example, the range of motion test may include registering thefemur with reference to a bone model (e.g., a preoperative plan), andregistering a tracker for the femur (the humerus or glenoid may beregistered and tracked for a shoulder procedure). The range of motiontest is then performed. The femur, the glenoid, or the humerus istracked throughout the range of motion test. The distance or pressure ata point or throughout a range (e.g., a maximum distance or pressure, ananimation of distance or pressure throughout the range of motion, or adistance or pressure at a selectable angle of range of motion) may bedisplayed on the user interface.

FIG. 3 illustrates an adjustable spacer and graphs 300 and 301 showingeffects of the adjustable spacer in accordance with some embodiments.The adjustable spacer may be used within a hip or shoulder, such as fora surgical procedure. The adjustable spacer may be used to measure,determine, or change a distance or pressure difference within a neck 308of a trial or implant for use with a femur, an acetabulum, a glenoid, ora humerus of a patient. For example, the adjustable spacer may be placedinto the neck 308 between a head 306 and a shaft 308 to be inserted intothe femur, the acetabulum, the glenoid, or the humerus. The adjustablespacer may be inflated to measure distance or pressure, for examplethroughout a range of motion test. The head 306 may fit into anacetabular component 310 (e.g., trial), as adjusted by the neck 308.

In the illustrated femoral stem/head prosthesis, the adjustable spaceroperates to shift the position of the femoral head portion 306 to extendor contract the neck 308 of the femoral stem. Adjusting the neck length(e.g., by extending or shortening the neck 308) may be an adjustment toa preoperative plan, for example based on a maximum pressure or distancedetermined during a range of motion test. In another example, theadjustable spacer may be located within the femoral head portion 306,and be used to determine an adjustment to the head size of the femoralhead (e.g., from a preoperative plan).

The adjustable spacer is shown in a first controlled configurationcorresponding to graph 300 and a second controlled configurationcorresponding to graph 301. The first configuration includes controllingthe adjustable spacer such that the pressure within the adjustablespacer is fixed. A fixed pressure means that the pressure output from apump or pumps is maintained within the adjustable spacer while distance(e.g., length or volume of the spacer) is allowed to fluctuate (e.g.,during a range of motion test).

Graph 300 illustrates changes in distance for the fixed pressureadjustable spacer throughout a range of motion test. Graph 300 has anx-axis illustrating degrees of the range of motion test. The y-axis ofgraph 300 illustrates a distance (e.g., in the example shown in FIG. 3 ,fluctuating between 0 and 30 mm). The graph 300 may be output to a userinterface on a display (e.g., a display of a robotic surgical system)for evaluation by a surgeon. In an example, a maximum or minimumdistance for the adjustable spacer may be determined from the range ofmotion test. The maximum or minimum distance may be used to adjust asurgical plan (e.g., a preoperative plan), such as by changing aparameter for a planned bone removal, changing an implant size, oradjusting soft tissue (e.g., releases). The changes to the preoperativeplan may be made automatically, for example changing a parameter of aplanned bone removal by a robotic arm. In an example, a change mayinclude determining a longer or shorter neck length for a trial orimplant or changing a cup size or cup position (of a trial or implantacetabular cup). For example, a user interface may be used to provide alength needed of implant neck to achieve the tested pressure (e.g., amaximum pressure).

The second configuration includes controlling the adjustable spacer suchthat the distance is fixed. A fixed distance means that the pressureoutput from a pump or pumps varies throughout a range of motion test forthe adjustable spacer. The adjustable spacer is thus fixed to a certaindistance, which may be determined as part of a preoperative plan orinteroperative change to a preoperative plan. The change in pressure maybe adjusted during a range of motion test to retain the fixed distance.The change in pressure may correspond to a change in force (e.g., 35 Nfor 7 psi and 52 N for 12 psi).

Graph 301 illustrates changes in pressure for the fixed distance in theadjustable spacer throughout a range of motion test. Graph 301 has anx-axis illustrating degrees of the range of motion test. The y-axis ofgraph 301 may illustrate a pressure (e.g., applied from a pump) or aforce applied by the or within the adjustable spacer (e.g., in theexample shown in FIG. 3 , a force is illustrated). The graph 301 may beoutput to a user interface on a display (e.g., a display of a roboticsurgical system) for evaluation by a surgeon. In an example, a maximumor minimum pressure for the adjustable spacer may be determined from therange of motion test. The maximum or minimum pressure may be used toadjust a surgical plan (e.g., a preoperative plan), such as by changinga parameter for a planned bone removal of the femur, the acetabulum, theglenoid, or the humerus, changing an implant size, or adjusting softtissue (e.g., releases). The changes to the preoperative plan may bemade automatically, for example changing a parameter of a plannedresection by a robotic arm. In an example, a change may includedetermining a longer or shorter neck length for a trial or implant. Forexample, a user interface may be used to provide a length needed ofimplant neck to achieve the tested pressure (e.g., a maximum pressure).

FIG. 4 illustrates a system 400 for using an adjustable spacer with arobotic surgical device in accordance with some embodiments. The system400 may include a robotic surgical system or device (e.g., a Rosa),which may include a user interface and a robotic arm. The roboticsurgical system or device may include a pump, be configured to hold orsupport a pump, interface with a pump, or the like. In another example,the system 400 may include a pump separate from the robotic surgicalsystem or device. The pump (which may include more than one pump) may beused to control an adjustable spacer. In the example where the pump iscontrolled by the robotic system or device, a processor of the roboticsystem or device may control pressure output to one or more componentsof the adjustable spacer. The robotic surgical system or device may beused to control the pump during a range of motion test, such as toevaluate distance or pressure in the adjustable spacer (e.g., during ahip or shoulder procedure).

FIG. 5 illustrates a flowchart showing a technique 500 for using anadjustable spacer in a surgical procedure, such as a shoulder or hipprocedure, in accordance with some embodiments. The technique 500includes an operation 502 to inflate (e.g., using a pump) an adjustablecomponent of an adjustable spacer (e.g., of an implant or a trial). Thetechnique 500 includes a decision operation 504 to determine whether afixed pressure or a fixed distance (or volume) is to be used for a rangeof motion test.

The technique 500 includes an operation 506 to, during a range of motiontest, maintain a fixed pressure in the component by allowing a distance(e.g., of a neck in a trial for a hip or shoulder implant) to change.The technique 500 includes an operation 508 to determine a maximumdistance during the range of motion test. The technique 500 includes anoperation 510 to, during a range of motion test, maintain a fixeddistance in the component by increasing or decreasing pressure (e.g.,using a pump). The technique 500 includes an operation 512 to determinea maximum pressure during the range of motion test.

In an example, the fixed distance or the fixed pressure may bedetermined using a preoperative plan. The preoperative plan may beadjusted based on the maximum distance or the maximum pressuredetermined during the range of motion test. In an example, an implant ora trial may be determined using the maximum distance or the maximumpressure. The maximum pressure or the maximum distance may be determinedusing a sensor (e.g., an iAssist device) or an optical tracker. In anexample, a change to a preoperative plan may include determining alonger or shorter neck length for a trial or implant. For example, auser interface may be used to provide a length needed of implant neck toachieve the tested pressure (e.g., a maximum pressure).

The technique 500 includes an operation 514 to output results fordisplay on a user interface, such as the maximum distance or the maximumpressure determined during the range of motion test. In an example,operations 506-508 may be done independently from operations 510-512,such as only doing one set of operations, or doing each set sequentially(e.g., fixed pressure range of motion test then fixed distance range ofmotion test, or vice versa). In an example, the fixed distance or thefixed pressure may be increased or decreased during a repeated range ofmotion test.

In an example, a surgical device used to operate the pump is a roboticsurgical device, and a processor may operate a robotic controller. Inthis example, the pump is controlled by the processor, and the roboticsurgical device includes a display, the display configured to presentthe user interface including the maximum pressure or the maximumdistance.

In an example, the pressure and the gap distance may be allowed tochange during the range of motion test. In this example, a 3D plan(e.g., a preoperative plan) may be used to set limits or targets for gapdistance or pressure. For example, a maximum pressure may be set fordifferent angles (e.g., from extension to flexion) or a maximum distancemay be set. The technique 500 may then proceed to, during a range ofmotion test, maintain a neck distance or pressure based on the 3D plan.At some portions of the range of motion test, the neck distance may beheld constant while at other portions of the range of motion test, thepressure may be held constant, according to the 3D plan. The technique500 may include an operation to determine a maximum pressure or maximumneck distance during the range of motion test (e.g., at differentportions of the test, based on when the neck distance or the pressure isheld constant, respectively).

FIG. 6 illustrates a system 600 for performing techniques describedherein, in accordance with some embodiments. The system 600 includes arobotic surgical device 602, which may be coupled to a pump 604 (in anexample not shown, pump 604 is a stand-alone pump, not coupled to arobotic device), which may be used to control a spacer device 606 (e.g.,an implant or a trial). The spacer device 606 includes an adjustablecomponent 608. The system 600 may include a display device 614, whichmay be used to display a user interface 616. The system 600 may includea control system 618 (e.g., a robotic controller), including a processor620 and memory 622. In an example, the display device 614 may be coupledto one or more of the robotic surgical device 602, the spacer device606, or the control system 618.

In an example, the display device 614 may be used to display results ofa range of motion procedure on the user interface 616. The results mayinclude distance or pressure information, such as over different anglesduring a range of motion test. The distance or pressure information maybe derived from a sensor, such as a sensor 610, which may be on theadjustable component 608 or elsewhere on or within the spacer device606. The sensor 610 may be a Hall effect sensor. The distance orpressure information may be related to a shoulder or hip joint.

FIG. 7 illustrates a block diagram of an example machine 700 upon whichany one or more of the techniques discussed herein may perform inaccordance with some embodiments. In alternative embodiments, themachine 700 may operate as a standalone device or may be connected(e.g., networked) to other machines. In a networked deployment, themachine 700 may operate in the capacity of a server machine, a clientmachine, or both in server-client network environments. In an example,the machine 700 may act as a peer machine in peer-to-peer (P2P) (orother distributed) network environment. The machine 700 may be apersonal computer (PC), a tablet PC, a set-top box (STB), a personaldigital assistant (PDA), a mobile telephone, a web appliance, a networkrouter, switch or bridge, or any machine capable of executinginstructions (sequential or otherwise) that specify actions to be takenby that machine. Further, while only a single machine is illustrated,the term “machine” shall also be taken to include any collection ofmachines that individually or jointly execute a set (or multiple sets)of instructions to perform any one or more of the methodologiesdiscussed herein, such as cloud computing, software as a service (SaaS),other computer cluster configurations.

Machine (e.g., computer system) 700 may include a hardware processor 702(e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 704 and a static memory 706, some or all of which may communicatewith each other via an interlink (e.g., bus) 708. The machine 700 mayfurther include a display unit 710, an alphanumeric input device 712(e.g., a keyboard), and a user interface (UI) navigation device 714(e.g., a mouse). In an example, the display unit 710, input device 712and UI navigation device 714 may be a touch screen display. The machine700 may additionally include a storage device (e.g., drive unit) 716, asignal generation device 718 (e.g., a speaker), a network interfacedevice 720, and one or more sensors 721, such as a global positioningsystem (GPS) sensor, compass, accelerometer, or other sensor. Themachine 700 may include an output controller 728, such as a serial(e.g., Universal Serial Bus (USB), parallel, or other wired or wireless(e.g., infrared (IR), near field communication (NFC), etc.) connectionto communicate or control one or more peripheral devices (e.g., aprinter, card reader, etc.).

The storage device 716 may include a machine readable medium 722 onwhich is stored one or more sets of data structures or instructions 724(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 724 may alsoreside, completely or at least partially, within the main memory 704,within static memory 706, or within the hardware processor 702 duringexecution thereof by the machine 700. In an example, one or anycombination of the hardware processor 702, the main memory 704, thestatic memory 706, or the storage device 716 may constitute machinereadable media.

While the machine readable medium 722 is illustrated as a single medium,the term “machine readable medium” may include a single medium ormultiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 724. The term “machine readable medium” may include anymedium that is capable of storing, encoding, or carrying instructionsfor execution by the machine 700 and that cause the machine 700 toperform any one or more of the techniques of the present disclosure, orthat is capable of storing, encoding or carrying data structures used byor associated with such instructions. Non-limiting machine readablemedium examples may include solid-state memories, and optical andmagnetic media.

The instructions 724 may further be transmitted or received over acommunications network 726 using a transmission medium via the networkinterface device 720 utilizing any one of a number of transfer protocols(e.g., frame relay, internet protocol (IP), transmission controlprotocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), Plain Old Telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as Wi-Fi®, IEEE 802.16 family ofstandards known as WiMax®, IEEE 802.15.4 family of standards,peer-to-peer (P2P) networks, among others. In an example, the networkinterface device 720 may include one or more physical jacks (e.g.,Ethernet, coaxial, or phone jacks) or one or more antennas to connect tothe communications network 726. In an example, the network interfacedevice 720 may include a plurality of antennas to wirelessly communicateusing at least one of single-input multiple-output (SIMO),multiple-input multiple-output (MIMO), or multiple-input single-output(MISO) techniques. The term “transmission medium” shall be taken toinclude any intangible medium that is capable of storing, encoding orcarrying instructions for execution by the machine 700, and includesdigital or analog communications signals or other intangible medium tofacilitate communication of such software.

Each of these non-limiting examples may stand on its own, or may becombined in various permutations or combinations with one or more of theother examples.

Example 1 is a surgical device for evaluating soft tissue during asurgical procedure comprising: a pump to: inflate an adjustable spacerin a neck portion of a femoral trial for a hip replacement procedure;and during a range of motion test, maintain a fixed distance in theadjustable spacer by increasing or decreasing pressure in the adjustablespacer; and a processor to: determine a maximum pressure during therange of motion test; and output the maximum pressure for display on auser interface.

In Example 2, the subject matter of Example 1 includes, wherein the pumpis further to decrease the fixed distance during a repeated range ofmotion test.

In Example 3, the subject matter of Examples 1-2 includes, wherein theprocessor is to use a preoperative plan to determine the fixed distance.

In Example 4, the subject matter of Example 3 includes, wherein theprocessor is further to adjust the preoperative plan based on themaximum pressure.

In Example 5, the subject matter of Examples 1-4 includes, wherein theprocessor is further to determine an implant based on the maximumpressure.

In Example 6, the subject matter of Examples 1-5 includes, wherein todetermine the maximum pressure, the processor is to use optical trackingof the neck portion of the femoral trial.

In Example 7, the subject matter of Examples 1-6 includes, wherein thesurgical device is a robotic surgical device, wherein the processoroperates a robotic controller, wherein the pump is controlled by theprocessor, and wherein the robotic surgical device includes a display,the display configured to present the user interface including themaximum pressure.

Example 8 is a method comprising: inserting a trial for a hipreplacement procedure, the trial including an adjustable spacer in aneck portion; inflating the adjustable spacer to a fixed distance; usinga pressure sensor device, measuring pressure on the adjustable spacerthroughout a range of motion test with the trial in place and theadjustable spacer inflated at the fixed distance; determining a maximumpressure during the range of motion test; and outputting the maximumpressure for display on a user interface.

In Example 9, the subject matter of Example 8 includes, decreasing thefixed distance and performing the range of motion test again.

In Example 10, the subject matter of Examples 8-9 includes, using apreoperative plan to determine the fixed distance.

In Example 11, the subject matter of Example 10 includes, adjusting thepreoperative plan based on the maximum pressure.

In Example 12, the subject matter of Examples 8-11 includes, determiningan implant based on the maximum pressure.

In Example 13, the subject matter of Examples 8-12 includes, determiningthe maximum pressure using an iAssist device.

Example 14 is a machine-readable medium including instructions forcontrolling an adjustable spacer of a trial inserted into a femur of apatient for a hip replacement procedure, which when executed by aprocessor, cause the processor to: cause the adjustable spacer toinflate to a fixed distance; receive pressure measurements from apressure sensor device, the pressure measurements taken by the pressuresensor device on the adjustable spacer throughout a range of motion testwith the trial in place and the adjustable spacer inflated at the fixeddistance; determine a maximum pressure during the range of motion test;and output the maximum pressure for display on a user interface.

In Example 15, the subject matter of Example 14 includes, wherein theinstructions further cause the processor to cause the fixed distance ofthe adjustable spacer to decrease, during a repeat of the range ofmotion test.

In Example 16, the subject matter of Examples 14-15 includes, whereinthe processor is further to use a preoperative plan to determine thefixed distance.

In Example 17, the subject matter of Example 16 includes, wherein theprocessor is further to adjust the preoperative plan based on themaximum pressure.

In Example 18, the subject matter of Examples 14-17 includes, whereinthe processor is further to determine an implant based on the maximumpressure.

In Example 19, the subject matter of Examples 14-18 includes, whereinthe processor is to receive the pressure measurements from an iAssistdevice.

Example 20 is at least one machine-readable medium includinginstructions that, when executed by processing circuitry, cause theprocessing circuitry to perform operations to implement of any ofExamples 1-19.

Example 21 is an apparatus comprising means to implement of any ofExamples 1-19.

Example 22 is a system to implement of any of Examples 1-19.

Example 23 is a method to implement of any of Examples 1-19.

Method examples described herein may be machine or computer-implementedat least in part. Some examples may include a computer-readable mediumor machine-readable medium encoded with instructions operable toconfigure an electronic device to perform methods as described in theabove examples. An implementation of such methods may include code, suchas microcode, assembly language code, a higher-level language code, orthe like. Such code may include computer readable instructions forperforming various methods. The code may form portions of computerprogram products. Further, in an example, the code may be tangiblystored on one or more volatile, non-transitory, or non-volatile tangiblecomputer-readable media, such as during execution or at other times.Examples of these tangible computer-readable media may include, but arenot limited to, hard disks, removable magnetic disks, removable opticaldisks (e.g., compact disks and digital video disks), magnetic cassettes,memory cards or sticks, random access memories (RAMs), read onlymemories (ROMs), and the like.

What is claimed is:
 1. A method, comprising: generating a preoperativeplan for a robotically-assisted hip arthroplasty; providing a roboticsurgical system having one or more integral pumps; performingrobotically-assisted burring of a patient's hip joint; inserting a trialin a proximal femur of the hip joint during a hip replacement procedure,the trial including an adjustable spacer in a neck portion; inflatingthe adjustable spacer to a fixed neck length; measuring force on theadjustable spacer throughout a range of motion test of the hip jointusing a force sensor device, with the trial in place and the adjustablespacer inflated at the fixed neck length; tracking a position of bonesof the hip joint utilizing an optical tracking system operativelycoupled to the robotic surgical system throughout the range of motiontest; determining a maximum force measured by the force sensor deviceduring the range of motion test; outputting the maximum force fordisplay on a user interface coupled to the robotic surgical system; andchanging a planned femoral implant size of the preoperative plan basedon the maximum force.
 2. The method of claim 1, further comprisingdecreasing the fixed neck length and performing the range of motion testagain.
 3. The method of claim 1, further comprising displaying theposition of the bones during the range of motion test on the display. 4.The method of claim 1, further comprising changing a parameter of aplanned bone removal by the robotic surgical system based on the maximumforce.
 5. The method of claim 1, further comprising changing at leastone of a cup size or a cup position of an implant acetabular cup basedon the maximum force.
 6. The method of claim 1, wherein inflating theadjustable spacer to the fixed neck length includes maintaining theadjustable spacer at the fixed neck length throughout the range ofmotion test by using at least one of the one or more integral pumps ofthe robotic surgical system to control pressure within the neck portionof the trial.
 7. The method of claim 6, wherein the at least one of theone or more integral pumps is controlled by a processor of the roboticsurgical system.
 8. The method of claim 1, wherein outputting themaximum force for display on the user interface includes displaying agraph showing measured force over time throughout the range of motiontest.
 9. The method of claim 1, further comprising displaying, on theuser interface, an indication that a measured force during the range ofmotion test exceeded a threshold.
 10. A method, comprising: generating apreoperative plan for the robotically-assisted hip arthroplasty;providing a robotic surgical system having one or more integral pumps;performing robotically-assisted burring of a patient's hip joint;inserting a trial in a proximal femur of the hip joint during a hipreplacement procedure, the trial including an adjustable spacer in aneck portion; inflating the adjustable spacer to a fixed pressure;measuring neck length on the adjustable spacer throughout a range ofmotion test of the hip joint using a sensor device, with the trial inplace and the adjustable spacer inflated at the fixed pressure; trackinga position of bones of the hip joint utilizing an optical trackingsystem operatively coupled to the robotic surgical system throughout therange of motion test; determining a maximum neck length measured by theforce sensor device during the range of motion test; outputting themaximum neck length for display on a user interface coupled to therobotic surgical system, and; changing a planned femoral implant size ofthe preoperative plan based on the maximum neck length.
 11. The methodof claim 10, further comprising decreasing the fixed pressure andperforming the range of motion test again.
 12. The method of claim 10,further comprising displaying the position of the bones during the rangeof motion test on the display.
 13. The method of claim 10, furthercomprising changing a parameter of a planned bone removal by the roboticsurgical system based on the maximum neck length.
 14. The method ofclaim 10, further comprising changing at least one of a cup size or acup position of an implant acetabular cup based on the maximum necklength.
 15. The method of claim 10, wherein inflating the adjustablespacer to the fixed pressure includes maintaining the adjustable spacerat the fixed pressure throughout the range of motion test by using atleast one of the one or more integral pumps of the robotic surgicalsystem to control pressure within the neck portion of the trial.
 16. Themethod of claim 15, wherein the at least one of the one or more integralpumps is controlled by a processor of the robotic surgical system. 17.The method of claim 10, wherein outputting the maximum neck length fordisplay on the user interface includes displaying a graph showingmeasured neck length over time throughout the range of motion test. 18.The method of claim 10, further comprising displaying, on the userinterface, an indication that a measured neck length during the range ofmotion test traversed a threshold.